This document relates to selecting computing resources from a pool of computing resources to perform a test.
Software and hardware can be efficiently tested by maintaining a pool of computing resources, and providing multiple tests to computing resources in the pool. To properly execute the tests, computing resources may be required to have certain hardware or software characteristics. For example, a user can define specific constraints on characteristics of computing resources, e.g., that the tests need to execute on computing resources that execute a particular version of an operating system.